Question

A 0.05-kg car starts from rest at a height of 0.95 m. Assuming no friction, what is the kinetic energy of the car when it reaches the bottom of the hill? (Assume g = 9.81 m/s2.)
A. 0.466 J
B. 0.308 J
C. 4.317 J
D. 0.0475 J

Answer 1

The kinetic energy of the car when it reaches the bottom of the hill is about A. 0.466 J

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Further explanation

Let's recall Kinetic Energy Formula as follows:

$\large {\boxed{Ek = \frac{1}{2}mv^2} }$

Ek = Kinetic Energy ( Joule )

m = mass of the object ( kg )

v = speed of the object ( m/s )

Let us now tackle the problem !

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Given:

mass of the car = m = 0.05 kg

initial speed of toy car = u = 0 m/s

initial height position of the car = h₁ = 0.95 m

final height position of the car = h₂ = 0 m

gravitational acceleration = g = 9.81 m/s²

Asked:

final kinetic energy of the car = Ek₂ = ?

Solution:

We will use Conservation of Energy to solve this problem:

$Ep_1 + Ek_1 = Ep_2 + Ek_2$

$mgh_1 + \frac{1}{2} m u^2 = mgh_2 + Ek_2$

$mgh_1 + \frac{1}{2} m (0)^2 = mg(0) + Ek_2$

$mgh_1 = Ek_2$

$Ek_2 = 0.05 \times 9.81 \times 0.95$

$Ek_2 \approx 0.466 \texttt{ J}$

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Learn more

• Impacts of Gravity : brainly.com/question/5330244
• Effect of Earth’s Gravity on Objects : brainly.com/question/8844454
• The Acceleration Due To Gravity : brainly.com/question/4189441
• Newton's Law of Motion: brainly.com/question/10431582
• Example of Newton's Law: brainly.com/question/498822

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Answer details

Grade: High School

Subject: Physics

Chapter: Energy

Answer 2

The kinetic energy of the car is A.) 0.466 J